853635 Mercruiser YOKE, Gear End

Illustration 1 g02725693
(1) Control valve
(2) Pressure sensor
(3) Check valve
(4) Actuators
Table 1
Diagnostic Codes for Mechanical Problems or Electrical Problems with the Intake Valve Actuation System
J1939 Code CDL Code Description Conditions Which Can Cause The Code
2949-7 1922-7 Intake Valve Actuation Oil Pressure not responding This code can only occur soon after the engine has started.
This code indicates that the difference in rail pressure is incorrect while the control valve is opened and closed. The following conditions can cause this code:
A control valve that contains debris or a control valve that is not operating correctly
Damaged O-ring seal or missing O-ring seal.
2950-7 1901-7 Intake Valve Actuator #1 not responding The intake valve actuator is not responding correctly to the commands from the ECM. This can be caused by the following conditions:
There is an oil leak in the system.
There is a problem with an actuator.
The valve lash is incorrect.
The adjustment of an actuator is incorrect.
2951-7 1902-7 Intake Valve Actuator #2 not responding
2952-7 1903-7 Intake Valve Actuator #3 not responding
2953-7 1904-7 Intake Valve Actuator #4 not responding
2954-7 1905-7 Intake Valve Actuator #5 not responding
2955-7 1906-7 Intake Valve Actuator #6 not responding
2948-7 E1101 (2) Engine Intake Valve Actuation System Oil Pressure : Not Responding Properly The Engine Intake Valve Actuation System Oil Pressure did not change when the Engine Intake Valve Actuation System Oil Pressure solenoid is toggled.
2948-17 E488 (2) Engine Intake Valve Actuation System Oil Pressure : Low - moderate severity (2) The Engine Intake Valve Actuation System Oil Pressure solenoid is commanded closed, but the oil pressure does not go up.
Follow the troubleshooting procedure in order to identify the root cause of the problem. Note: Resolve any electrical problems with the system before you use this procedure.SymptomsThe following symptoms may occur if there is a problem with the intake valve actuation system.
Intermittent check engine light
Intermittent reductions in engine powerYou may need to apply a load to the engine in order to verify that the problem is resolved. The test must be performed at 75 percent of the engine's rated fuel rate for at least 30 seconds.
Table 2
Troubleshooting Test Steps Values Results
1. Check the Engine Oil Level
A. Stop the engine. Allow the engine to cool approximately 20 minutes so the oil level can stabilize.
B. Check the engine oil level.
Oil level
Result: The engine oil level is OK.
Record the engine oil level. Verify that the dipstick is calibrated correctly. Refer to Operation and Maintenance Manual, "Engine Oil Level Gauge - Calibrate".
Proceed to Test Step 2.
Result: The engine oil level is low.
Verify that the dipstick is calibrated correctly. Refer to Operation and Maintenance Manual, "Engine Oil Level Gauge - Calibrate".
Add engine oil to the proper level. Record the amount of engine oil that was added. Verify that the repair resolved the problem.
If the problem has not been eliminated, proceed to Test Step 2.
Result: The engine oil level is high.
Verify that the dipstick is calibrated correctly. Refer to Operation and Maintenance Manual, "Engine Oil Level Gauge - Calibrate".
Record the amount of engine oil that was drained. Verify that the repair resolved the problem.
If the problem has not been eliminated, proceed to Test Step 8.
Table 3
C18 Oil Pressure Table
Engine Speed Pressure (kpa) Pressure (psi)
800 233 34
1400 326 47
1800 420 61
2100 503 73
Illustration 2 g02725393
C18 oil pressure map
Table 4
Troubleshooting Test Steps Values Results
2. Check the Engine Oil Pressure
A. Turn the keyswitch OFF.
B. Establish communication between the Caterpillar Electronic Technician (ET) and the engine ECM. The communication adapter must be communicating on both data links in order to perform this procedure. Refer to Troubleshooting, "Electronic Service Tools" for more information, if necessary.
C. Install a mechanical gauge to the engine in order to read engine oil pressure. Refer to Testing and Adjusting, "Engine Oil Pressure - Test".
D. Turn the keyswitch OFF.
Oil pressure ( Refer to Table 3)
Result: The engine oil pressure is within specifications.
Proceed to Test Step 3.
Result: The engine oil pressure is low.
Record the engine oil pressure.
Record the engine rpm.
If there are any active diagnostic codes that are related to low oil pressure, refer to the appropriate topic in Troubleshooting, "Oil Pressure Is Low".
If the pressure is constant throughout the rpm range, there is a problem with the circuit for the engine oil pressure sensor. Check the wire for the pressure sensor supply (terminal A) for an open circuit.
If there are no diagnostic codes that are related to low oil pressure, refer to Testing and Adjusting, "Engine Oil Pressure - Test".
Verify that the repair resolved the problem.
Table 5
3. Determine the Logged Code
A Connect to Cat ET.
B. Turn the keyswitch ON.
C. Check for active or logged diagnostic codes:
Codes
Result